The number 42118
42118 is a composite number with 4 divisors. Its prime factorisation is 2 × 21059. Divisors (4): 1, 2, 21059, 42118.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 42118: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 2 × 21059, the product of two primes.
- 2
42118 is composite. Its prime factorisation is
- 3
The divisors add up to 63180; without 42118 itself that is 21062, so 42118 is deficient (21062 is less than 42118). Euler's totient φ(42118) = 21058 numbers up to 42118 share no factor with it.
- 4
The digits of 42118 add up to 16, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 44 steps to reach 1.
LaTeX source of the formulas on this page
\[ 42118 = 2 \times 21059 \]
42118 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 63180 |
| Euler totient φ(n) | 21058 |
| Square | 1773925924 |
| Cube | 74714212067032 |
| Square root | 205.226704 |
| Digit sum / digital root | 16 / 7 |
| Collatz steps to 1 | 44 |
| Scientific notation | 4.2118 × |
42118 in other forms
| Form | Value |
|---|---|
| In words | forty-two thousand one hundred and eighteen |
| Binary (base 2) | 1010010010000110 |
| Octal (base 8) | 122206 |
| Hexadecimal (base 16) | A486 |
| Base 3 | 2010202221 |
| As time | 42118 seconds = 11 h 41 min 58 s |
Is 42118 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (42118 ÷ 2 = 21059) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | No (remainder 1) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 2) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 3) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 4) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 6) | A number is divisible by 7 if double the last digit and subtract it from the rest: the result is a multiple of 7. |
| 8 | No (remainder 6) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 7) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 8) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 10) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 10) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 42118 a prime number?
No. 42118 = 2 × 21059, so it is divisible by 2.
What are the factors of 42118?
1, 2, 21059, 42118.
What is 42118 in binary?
1010010010000110 (hexadecimal A486, octal 122206).
What is the square root of 42118?
About 205.2267.
Is 42118 divisible by 3?
No. Its digits add up to 16, which is not a multiple of 3.
What is special about the number 42118?
42118 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 2 × 21059, the product of two primes.